Integrating dual-purpose crops mitigates feedbase risk and facilitates improved lamb production systems across environments: a whole-farm modelling analysis

Context The winter feed gap is a common problem for livestock grazing systems worldwide, and changes to climate have made these deficits more unpredictable extreme. Dual-purpose crops are an important tool in many southern Australian mixed crop–livestock help fill the gap. Providing reliable over can remove constraints allow earlier lambing autumn with potential whole-farm system benefits. Aims We simulated enterprise Agricultural Production Systems Simulator (APSIM) examine implications of spring- autumn-lambing relying on standard pasture-only feedbase compared farm where 25% its grazed area allocated dual-purpose crops. Methods Twelve simulations were run across four locations New South Wales, Australia, that varied climatic conditions (both rainfall total distribution) including two (spring vs autumn) × types (100% pasture 75% crops) three stocking densities. Key results For systems, integrating helped reduced supplement demand average by ~28% system. Compared spring-lambing system, into than doubled gross margin returns due economic grain yield lower demand. A shift from facilitated also led better reproductive performance ewes subsequent year. In higher-rainfall, cooler environments, had highest margins, lowest risk allowed safe increase density. lower-rainfall, warmer integration returned marginally higher margins but differences less apparent at high lower-rainfall mitigate some risk, benefits clear. Conclusions show support range especially higher-rainfall significant improvements margins. Implications Integrating will enable farmers change their risks, reduce supplementary feeding capitalise other benefits, such as improved marketing avoiding animal health problems.